Electrical starting system for automobiles



Aug. 26, 1930. L. K. LOEHR ET ELECTRICAL STARTING SYSTEM FOR AUTOMOBILES Filed Dec. 6, 1926 pendent upon the current PM Aug. 2a; 1 30 UNITED STATES PATENT" OFFICE LESLIE K. 1.0m AND WAYNE E. BUBDIOK, OF

SAN FRANCISCO, CALIIOBNIA, AS-

SIGHOBS, BY IESNE ASSIGNKENTS, TO THE STAB'IOMATIO CORPORATION, A 003' POBATION OF NEVADA.

ELECTRICAL STARTING. SY S'IEH FOB AUTOMOBILES Application filed December 6, 1928. Serial K0. 152,913.

' 8 mobile englnes.

Our invention has for its object to provide a system for actuating the starting motor of an automobile engine incident to the turning on of the ignition switch and relative to the 1 stationary and rotary condition of said en- A more specific ob'ect of our invention is to provide a means w ereby the starting m0- tor is disconnected from its source of energy after the engine has been started and to further provide a means for automatically reconnecting the starting motor with the said sourceof energy in case the engine ceases to rotate, for any reason other than the willful operation of the said ignition switch and this condition to exist, as long as the said ignition switch is turned on. I

Another object is to provide a means destrength passing "through the starting motor for maintaining the connection of said motor to a source of energy as long as the starting motoris rotating the engine and for disconnecting the said motor from said source of energy after the engine has started.

A further object of this invention is to provide a lock-out means for preventing the operation of the starting motor while the engine is rotating under its own power and said lock-out means to automatically respond and cause the starting motor to rotate the engine should the same stop for any reason other than theintended operation of the ignition switch.

In the operation of an automobile it is found to be very convenient for the driver to be concerned with only the ignition switch when starting the engine and especially when driving in congested trafiic, or when driving an automobile up a grade, or over a railroad crossing and the engine is stalled through inadvertence or by accident where a delay in starting the engine might result in serious happenings.

x e provide in this mventlon a means for automatically starting a stalled engine and sa1d ineans being capable of causin the starting motor to propel the automobile so equipped to a place of possible safety in the event of failure on the part of the en M to start in response to the rotation by sai starting motor.

It has been an effort in the design of this device to provide a simple, effective means to fulfill t e objects mentioned herein and to be dependent solely upon the starting conditions, and said means to provide a positive lock-out to prevent theoperation of the start ing motor until the engine has ceased to rotate under its 'own power at its minimum speed.

These and other objects will appear as our invention is more fully hereinafter pointed out in the accompanying drawings, described in the following specification and finally pointed out in the appended claims.

Referring to the drawings in which like reference numerals indicate like parts:

Fig. 1 is a diagrammatic view of the circuits and parts of the apparatus of our invention showing a preferred form as applied to an internal combustion engine of the type used in automobiles.

Fig. 2 is a diagrammatic view of our invention showing a modification in the wiring thereof.

Reference numeral 5 indicates an internalcombustion engine havingattached thereto a starting motor 6, which is arranged with suitable means for rotating the crankshaft of engine 5 by reason of the pinion 7 engaging the gear 8 on the flywheel 9, and said means providing for the disengagement of the gears 7 and 8 after the engine begins to rotate under its own power at a higher rate than cranking spee Numeral 10 indicates a generator that is driven by suitable means, not shown, from the engine 5. A reverse current relay 11 operates in conjunction with the generator 10 to open and close a circuit 12 having in series therewith a storage battery 13 and ground connections 14-an 15. A ma lietically operated starting switch 16 embodying a coil 17 is arranged to'open and close a circuit 18 having in series therewith coils 19 and 20, ofthe magnetic lock-out device 21, starting motor 6, grounds 22 and 14, and battery 13. An ignition switch 23 embraced in a circuit 24 and in series with an ignition coil 25, serves to connect the coil 17 of magnetic switch 16 with the battery 13 by reason of th the contacts 26 and 27, grounds 28 and 14.

A shunt winding 29 wound on the core 38 in a manner to assist the winding 20, of the magnetic lock-out device 21, is connected directly across the terminals of generator 10 by means of the circuit 30 and ground connections 15 and 28.

A spring 31 normally holds the armature 32 in definite relation, with the core 33, and since the contact 27 is rigidly mounted to the armature 32, by means of the arm 34, the said spring 31 serves to hold the contacts 26 and 2? closed. A second armature 35 is held in an open position by spring36 which has one end securely fastened to the armature 32; while the other end is slideably mounted on the armature 35. The said armatures 32 and 35 are pivoted on a pin 37 in a manner to permit their free and independent movement of each other. and any relation restricting such movement is aifo ded by the springs 31 and 36.

The operation of our invention is as follows:

When it is desired to start the automobile engine the ignition switch 23 is closed and current is caused to flow from the battery 13 through part of the circuit 18 and circuit 24 into the ignition coil 25 and incidentally current flows through the coil 17 of switch 16, through the contacts 26 and 27, back to the battery 13 by way of ground connections 28 and 14, thereby causing magnetic induc tion in the said switch 16 resulting in the closing of the circuit 18. Current now flows through the coils 19 and 20, of the look-out device 21. and into the starting motor 6, and back to the battery 13 by way of grounds 22 and 14. This causes a magnetic induction to exist in the cores 33 and 38, respectively, which exerts a pull on the armatures 32 and 35. This pull assists the spring 31 to hold the armature 32 into definite relation with the core 33, while the armature 35 is drawh down close to the core 38 against the urge of spring 36. The current passing through the starting motor 6 varies inversely as the speed thereof, therefore, during the operation of cranking the engine 5 more current passes through the starting'motor 6. and the circuit 18 embracing the coils 19 and 20. of the lockout device 21, than when said motor is rotating free of engagement and without load. This condition is due to the inherent tendency of the motor to develop a counter electromotive force which varies directly as the speed of said motor resulting in a greater curl is .of the spring rent passing through the motor under load than when spinning free without load.

The magnetic lock-out device 21 makes use of the condition just described by means of the coils 19 and 20 whose magnetic linkages vary with the current passing thro igh em. The armature 32 is separated from the core 33 by an air gap 39 of greater length and a consequent greater reluctance than the gap which separates the armature 35 and the core 38 when said armature is drawn close to said core. A greater pull is therefore exerted upon the armature 35 than is exerted upon the armature 32, even though the magnetic induction is equal at both core ends; since permeance, which is the reciprocal of reluctance, increases at a very high rate as the armature approaches the core end; so that the pull, for a given number of turns (squared), varies approximately as the inverse square of the distance between the core end and the armature. Permeance expressing the degree of ease with which the magnetic flux is produced.

The tension of spring 36 is adjusted to exceed the tension of spring 31 by a sufficient amount to overcome the magnetic pull. exerted upon the armature 32 by the core 33 at any predetermined amperage passing through the starting motor 6 and the coils 19 and 20; since the magnetic induction and resultant pull varies with the flow of current through said coils.

While the starting motor 6 is cranking the engine 5 sufiicient current passes through the coils 19 and 20 to permit the core 33 to hold the armature 32 in the position as shown in the drawing and to allow the core 38 to draw the armature 35 into close relation with the end of said core 38. The contacts 26 and 27 remain closed by reason of the combined pull 31 and the magnetic attraction of the core 33 until after the engine is started and the motor 6 is disengaged from rotative connection with said engine whereupon the said motor 6 increases its speed, being without load, thereby increasing the value of the counter electromotive force which causes a reduced flow of current through the starting motor 6 and coils 19 and 20. The magnetic attraction on the armature 32 is reduced sufficiently, under the above condition, to allow the spring 36 to overcome the magnetic pull and the pull of spring 31 on the armature 32 thereby moving the said armature away from the core 33 and causing the contacts 26 and 27 to open which interrupts the flow of current through the coil 17 of magnetic switch 16, allowing the said switch to open the circuit 18 and stop the flow of current through the starting motor 6.

Assuming the engine 5 to be rotating under its own power and therefore driving the generator 10; voltage created in said generator causes current to flow through the coil 29, which comprises a relatively large number of turns of small diameter wire, in an amount sufiicient to hold the armature 35 into close relation with the core 38 overcoming the spring 31, by reason of the stronger spring 36. The coil 29 is so designed that a relatively high magnetic flux exists through the ferro-magnetic circuit comprising the core 38 and the leg 40 when only a very low voltage and a consequent low current value passes through the said coil and thereby permitting an adequate pull on the armature 35 to overcome the spring 31. The generator 10 must cease functioning, or substantially so, before the armature 35 can return to its normal open position, as disclosed in the drawing. Such a condition will permit the contacts 26 and 27 to close, and if the ignition switch 23 is closed, current again passes through the coil 17 and the condition for starting the. engine 5 prevails in the manner previously set forth.

In the modification illustrated by Fig.-2 conditions and the method of operation are substantially the same as in Fig.1 with the exception of the shunt 41 which carries part ofthe currentto the starting motor 6 while a small amount flows through the coils 19 and 20 of Fig. 2.

The shunt 41 has a normal current carrying capacity equal to the spinning amperage of the motor 6 so that a very low current value passes through the coils 19 and 20 when the said motor is spinning free without load. The rotating of the engine by the motor 6 causes more current to flow through the shunt 41 and consequently more current passes through the coils 19 and 20 creating suificient magnetic flux to operate the lockout device 21 in the manner describing the function of said device in Fig. 1.

From the foregoing description taken in connection with the accompanying drawings the advantage of the construction and of the method of operation of our device will be readily apparent to those skilled in the art to which the invention relates, but, while we have described the principle of operation of the invention together with. the device which we now consider to be the best embodiment thereof, we desire to have it understood that the device is merely illustrative and that such changes may be made as are within the scope and spirit of the appended claims.

We claim as our invention:

1. The combination with an internal combustion engine and a means for cranking said engine embodying an electric starting motor, of a means for controlling the operation of said startin motor and means for operating said control ing means, said operating means being energized by the current passing through the starting motor and automatically operative incident to variation of the current strength passing through said starting motor to cause the controlling means to open the starting motor circuit when the starting current drops to a predetermined minimum, and to cause the controlling means to reclose thestarting motor circuit when'said o erating means is substantially deenergize 2. The combination with an internal combustion engine and a means for starting said engine embodying an electric starting motor and'a source of current in .circuit therewith, of an electromagnetic switch for controlling the motor circuit and a means for operating said switch which means operates incident to predetermined variations of the current strength passing through the starting motor to cause said electromagnetic switch to open said motor circuit upon a predetermined drop of current in said motor circuit and to cause said electromagnetic switch to reclose said motor circuit when said operating means becomes substantially de-energized.

3. The combination with an internal combustion engine, a starting motor for said engine having a means for rotatively connecting said devices and for disconnecting same after the said engine has been started, and a source of current, of an electromagnetic switch for connecting said motor to said source of current and a second magnetic switch dependent upon the flow of current throu h said starting motor to cause said first e ectromagnetic switch to open said motor circuit upon a predetermined drop of current in said motor circuit and to cause said first electromagnetic switch to reclose said motor circuit when said second electromagnetic switch becomes de-energized.

4. The combination with an internal combustion engine, a starting motor embodying a means for rotatively connecting said motor and said engine and for disconnecting same after said engine has been started, a source of current, and an ignition circuit having a manually operated switch disposed therein, of an electromagnetic switch for connecting said motor to said source of current and said magnetic switch being connected to said source of current incidental to the operation-of the first named switch and a second magnetic switch dependent upon the flow of current through said starting motor to cause said first electromagnetic switch to open said motor circuit upon a predetermined drop of current in said motor circuit and to cause said first electromagnetic switch to reclose the motor circuit when said second electromagnetic switch becomes deenergized.

5. The combination with an internal combustion engine, a starting motor embodying a means for rotatively connecting said motor and said engine and for disconnecting same after said engine has been started, a stor age battery, and an ignition circuit having a manually operable switch disposed therein, of an electromagnetic switch for connecting said motor to said storage battery and said magnetic switch being connected to said storage battery by the operation of the first named switch, a switching mechanism arranged to open and close the circuit embracing said electro magnetic switch and a means of operation of said switching mechanism dependent upon the rotative speed of said starting motor, and a speed responsive means embodied within said switching mechanism for holding said circuit open until said engine ceases to rotate.

6. In combination, an electric generator, 9. storage battery, an electric starting motor in circuit therewith, and a means for controlling the operation of said motor operating incident to the variation of current values passing through said motor and incident to the voltage created in said generator.

7. The combination with a source of current and an electric motor in circuit therewith and a switch for controlling the motor circuit including an electro-rnagnet, of a switch for controlling the operation of said electro-magnet having a winding in circuit with said motor, and a generator in circuit with a second winding which is arranged to cooperate with the first named winding.

8. The combination with an internal com bustion engine, a starting motor embodying means for rotatively connecting said motor to said engine, a storage battery in circuit with said motor, of a switch disposed within said circuit, a means for causing said switch to open said circuit which means is dependent for its operation upon the reduced flow of current through said motor after said engine has been started, and a speed responsive means to prevent the operation of said switch to close the said circuit until said engine ceases to rotate.

9. The combination with an internal com bastion engine, a starting motor embodying a means for rotatively connecting said motor to said engine, a storage battery in circuit with said motor, of an electromagnetic switch disposed within said circuit, a second circuit embracing the coil of said electromagnetic switch having disposed therein an electro-responsive means adapted to open and close the second named circuit in response to predetermined rotative conditions of said engine and said motor, said electro-responsive means comprising a winding in series with said storage battery and said motor subject to the variation of current values passing through said motor, and a winding in series with a source of current whose voltage varies with the speed of said engine.

10. The combination with an internal combustion engine, a starting motor adapted to rotate said engine, a storage battery in circuit with said motor, of an electromagnetic switch disposed within said circuit comprising a coil, a. second circuit having disposed 

